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(nasm.info)Section 10.1.4

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10.1.4. `TIMES' Doesn't Work
----------------------------

   The other common problem with the above code is people who write the
`TIMES' line as

             TIMES 510-$ DB 0

   by reasoning that `$' should be a pure number, just like 510, so the
difference between them is also a pure number and can happily be fed to
`TIMES'.

   NASM is a _modular_ assembler: the various component parts are
designed to be easily separable for re-use, so they don't exchange
information unnecessarily. In consequence, the `bin' output format,
even though it has been told by the `ORG' directive that the `.text'
section should start at 0, does not pass that information back to the
expression evaluator. So from the evaluator's point of view, `$' isn't
a pure number: it's an offset from a section base. Therefore the
difference between `$' and 510 is also not a pure number, but involves
a section base. Values involving section bases cannot be passed as
arguments to `TIMES'.

   The solution, as in the previous section, is to code the `TIMES' line
in the form

             TIMES 510-($-$$) DB 0

   in which `$' and `$$' are offsets from the same section base, and so
their difference is a pure number. This will solve the problem and
generate sensible code.